Naomi Osaka of Japan attends a news conference upon her arrival in Japan, after winning the women's singles finals tennis match at the 2018 U.S. Open, in Yokohama September 13, 2018. "You're told to just turn around and try to focus, so I tried to do that, but in my mind I was sort of - like I really wanted to know what was going on".

If the monster contract goes through, it would be the biggest deal the apparel giant has ever given to a female tennis player and could propel Osaka up the ranks on Forbes' 2018 list of highest paid female athletes, which Williams now leads.

The Women's Tennis Association also backed Williams, with their CEO Steve Simon saying, "The WTA believes that there should be no difference in the standards of tolerance provided to the emotions expressed by men versus women".

There are now discussions about boycotting Williams' matches between a group of umpires that lack a body to represent their interests.

The Times reported that the incident has sparked outrage among umpires and they are coming together as a profession. Navratilova said, "It wasn't the right time to bring it up", and that she would have expected to face similar penalties for acting as Williams did.

The former world No 1 then proceeded to smash her racket and was deducted a point before she was later forced to forfeit a game after she continued her row with umpire Carlos Ramos.

Williams accused Ramos of sexism after the match and pointed out that male players have been more aggressive verbally with umpires than she was, but had been not been penalized the same way.

"I have had lots of messages saying this is a joke", said one source. That triggered a third violation, which resulted in a game penalty that gave Osaka a 5-3 lead.

"The point is he (Ramos) aggravated the situation, instead of "I'm not attacking your character" which is the most important thing he could have said".

"The Sept 10 cartoon not only exudes racist, sexist caricatures of both women, but Williams' depiction is unnecessarily sambo-like", the association said in a statement.